SaunaModel.jl Guide
Warming up with Differential Equations and Unitful.
This package is estimate of how a lumped sum sauna would behave. A lumped sum system modeling means approximating each component of the system with one number. This is a rough and ready approximation: obviously, the stove isn't all one temperature, and the air has has a very complex fluid dynamics problem, which could heat a small sized sauna with the heat given off with all the computers needed to solve in granular detail.
You might ask why would I sink the time into modelling a sauna with differential equations. It sprung from a group chat where we were discussing the impact of adding a water tank to a sauna. I fired off some real preliminary calculations, then said I didn't have the time to write up the differential equations to do it right. The problem stuck with me, and I figured I had enough discussions abouth the thermal dynamics of a sauna to bump out a solution.
The current active usage of this package is saunasim, deployed by Mark Halonen
Development of the model relied on several discussions with Trent Johnson and Chet Daavetila.
Video of Steam Throwing
To get a rough idea what steam throwing looks like thermally: 
Examples
Commentary on development
I developed the model in Julia for a couple of reasons. First, it is my daily driver language, it is what I use all the time. It also offers some excellent unit and differential equations packages. I used a functional approach as far as possible, avoiding side effects other than what is dictated by the Differential Equations package. This should make the code base easier to maintain.